The present disclosure relates to a methodology for optical proximity correction (OPC) that employs multiple OPC programs based on multiple process models and a system for implementing the same.
OPC is employed to enable printing of lithographic shapes affected by the wave nature of irradiating light in lithographic processes. OPC is particularly useful when the lithographic shapes to be printed include sublithographic features, i.e., features having a dimension less than a minimum printable hole, line, or spacer.
OPC methodology as known in the art typically employs a single OPC program employing a same set of parameters for the entire design layout. The set of parameters in an OPC program includes, for example, fragments and number of iterations. Further, OPC methodology as known in the art employs a single process model that is applied to the entirety of a design layout. The single process model includes a single resist model.
Thus, the OPC methodology as known in the art employs the same OPC program irrespective of the sensitivity of various patterns within a design layout. Further, because resist development characteristics and cross-sectional shapes are different at different process conditions corresponding to a different set of lithographic does and depth of focus, a single process model employing a single resist model does not represent the entire range of process variations.